Actors Access sides distribution site for actors
Showfax is where actors get their sides. It is part of Breakdown Services, the same company behind Actors Access, so the audition you submitted for and the material you read from sit in the same system.
Sides are the pages of script you are asked to prepare. Getting them early is the whole point: the difference between a rushed cold read and a prepared one is usually a few hours with the pages rather than talent.
Membership covers downloads and some sides are posted free. Whether it is worth paying for depends on how often you audition in a market that runs on Breakdown Services, which in the United States is most film, television and theatrical casting.
One practical habit: download sides as soon as they are released, not the night before. Sides get revised, and the version you rehearsed is not always the version in the room.